摘要
以白桦1年生实生苗为试材,分别用37℃与42℃高温处理2、4、8、122、4 h,以常温处理(白天25℃1、2 h/夜间15℃1、2 h)苗木为对照,对其叶片叶绿素含量、根系活力、可溶性糖含量、超氧化物歧化酶(SOD)活性、超氧阴离子(O2.-)含量、丙二醛(MDA)含量、蛋白质含量和电阻抗进行测定,研究其抗热性。结果表明:37℃处理的叶片中叶绿素含量低于对照,SOD活性和MDA含量高于对照;42℃处理的叶片中叶绿素含量、根系活力、可溶性蛋白含量、MDA含量和弛豫时间τ低于对照,SOD含量和胞外电阻(re)高于对照;并且42℃处理的叶片中叶绿素、可溶性糖、SOD活性高于37℃处理,而可溶性蛋白、O2.-、MDA含量和根系活力较37℃处理低。37℃下,胞内电阻(ri)与MDA含量呈显著正相关(r=0.68),β系数与可溶性糖含量呈显著负相关(r=-0.75),胞内电阻(ri)与可溶性蛋白含量呈显著正相关(r=0.75);42℃下,胞外电阻(re)与可溶性糖含量成显著正相关(r=0.91),胞内电阻(ri)与SOD活性成显著负相关(r=-0.51)。37℃与42℃处理下的电阻抗图谱参数差异显著,胞外电阻(re)、胞内电阻(ri)、弛豫时间τ和β系数变化规律不一致。研究发现,42℃是高温胁迫下诱导白桦幼苗抗热性的更理想条件;用电阻抗图谱法研究白桦幼苗的抗热性是可行的。
To study the heat tolerance of Betula platyphylla Suk.,chlorophyll content,root vitality,soluble sugar content,superoxide dismutaseon(SOD) activity,superoxide anion(O-·2) content,malondialdehyde(MDA) content,soluble protein content and electrical impedance spectroscopy(EIS) parameters were tested in leaves of one-year-old B.platyphylla Suk.seedlings.Heat stress temperatures of 37℃ and 42℃ were used with 2 h,4 h,8 h,12 h and 24 h treatment,respectively.Seedlings with 25℃,12 h(day)/15℃,12 h(night) were as control samples.The results indicated that under 37℃ treatment,chlorophyll content was lower,while SOD activity and MDA content were higher than those of the control.Under 42℃ treatment,chlorophyll content,root vitality,soluble protein content and relaxation time(τ) were lower,while SOD activity and extracellular resistance(re) were higher than those of the control.Under 42℃ treatment,chlorophyll content,soluble sugar content and SOD activity were higher,while soluble protein,O-·2,MDA content and root vitality were lower than those treated under 37℃.Under 37℃ treatment,there was a significant positive correlation between intracellular resistance(ri) and MDA content as well as a significant negative correlation between β and soluble sugar content.The ri and soluble protein content correlated positively.Under 42℃ treatment,extracellular resistance(re) significantly positively correlated with soluble sugar content,and ri significantly positively correlated with SOD activity.The changes of re,ri,relaxation time(τ) and β behaved differently between 37℃ and 42℃ treatments.In conclusion,the heat tolerance of birch seedlings tested by physiological and biochemical indexes suggests that 42℃ is an ideal condition to induce heat tolerance under high temperature stress compared with 37℃ treatment;and the EIS method is suitable for determining heat tolerance of birch seedlings.
出处
《西北植物学报》
CAS
CSCD
北大核心
2010年第9期1844-1851,共8页
Acta Botanica Boreali-Occidentalia Sinica
基金
河北省自然科学基金(C2008000256)
河北农业大学留学回国人员科研启动基金(200406)
关键词
白桦
幼苗
高温胁迫
生理生化指标
电阻抗图谱
抗热性
Betula platyphylla Suk.
seedlings
high temperature stress
physiological and biochemical indexes
electrical impedance spectroscopy
heat tolerance